LU-2505 osc: use GFP_ATOMIC for ll_dirty_page_discard_warn()

Because it can be called inside client obd list lock as follows:

        ll_dirty_page_discard_warn at ffffffffa0a3d252 [lustre]
        vvp_page_completion_common at ffffffffa0a7adfc [lustre]
        vvp_page_completion_write_common at ffffffffa0a7ae6b [lustre]
        vvp_page_completion_write at ffffffffa0a7b83e [lustre]
        cl_page_completion at ffffffffa05eed8f [obdclass]
        osc_completion at ffffffffa0880812 [osc]
        osc_ap_completion at ffffffffa086a544 [osc]
        brw_interpret at ffffffffa0876d69 [osc]

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: I04a4cc1142e019d39dccf2c1f3084c0298acff9d
Reviewed-on: http://review.whamcloud.com/4870
Tested-by: Hudson
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>

diff --git a/lustre/llite/llite_lib.c b/lustre/llite/llite_lib.c
index 5615283..2b0e667 100644 (file)
--- a/lustre/llite/llite_lib.c
+++ b/lustre/llite/llite_lib.c
@@ -2435,7 +2435,8 @@ void ll_dirty_page_discard_warn(cfs_page_t *page, int ioret)
        struct dentry *dentry = NULL;
        struct ccc_object *obj = cl_inode2ccc(page->mapping->host);
 
-       buf = (char *)__get_free_page(GFP_KERNEL);
+       /* this can be called inside spin lock so use GFP_ATOMIC. */
+       buf = (char *)__get_free_page(GFP_ATOMIC);
        if (buf != NULL) {
                dentry = d_find_alias(page->mapping->host);
                if (dentry != NULL)